An intense day of testimony in the McDonnell trial has ended with one of the McDonnell's closest advisors talking about a meltdown by Maureen McDonnell. Jonnie Williams also explained the now infamous email between him and the former first lady about sex, saying he had nothing to it.

Star witness Jonnie Williams did everything he could today to quell any idea of a relationship between him and Maureen McDonnell. But the government had another bombshell Monday, drawing Mitt Romney and his family into the drama.

It's a quick exit for Jonnie Williams, but the impact of his testimony will last for weeks. A dramatic admission from Williams on the stand, saying five times within two minutes: "I just know what I did was wrong..." adding later, “It couldn’t be right for me to be paying all this money.”

The infamous email came up once again, this time with the prosecution asking what it was really about. His way of explaining it?

Williams said: "It’s just an odd message you get.”

At one point, Judge Spencer asked Williams point blank, if he ever had a sexual relationship with the former First Lady.

Williams' response: "I never had any physical contact with Mrs. McDonnell… and I didn't know she had any interest in me until last week."

Then late Monday, a top political advisor to McDonnell, Phil Cox, took the stand.

Cox said he was the one who told the First Lady Williams couldn't buy her a $20,000 Oscar de la Renta dress.

Cox testified Maureen McDonnell sent him an email, saying, "It was an insane rant on Christmas Eve."

The former political advisor also testified that Maureen and Williams tried to meet with Mitt Romney while he was running for president. Their mission: to push Williams' pill, Anatablock, as a cure for MS.

Cox said, "I have a recollection of asking what the heck he (Jonnie Williams) was doing there… his product was a cure for everything.”

The defense fought back on that episode with Mitt Romney, saying that it's typical for politicians to bring donors on trips with them.

There is now the expectation that Romney could testify here, adding even more drama to the spectacle.

Former Virginia Governor Bob McDonnell leaves the courthouse after his wife, Maureen, was sentenced to one year in prison (Source: NBC12)

Experts tell NBC12, they weren't surprised by Friday's decision from the Supreme Court that it would hear McDonnell's case. When it's all said and done – one of three things could happen:

Experts tell NBC12, they weren't surprised by Friday's decision from the Supreme Court that it would hear McDonnell's case. When it's all said and done – one of three things could happen McDonnell could go to prison, walk free or have a new trial right here at the federal courthouse, where this all started.. “I